Billede galleri - hjælp

Jeg har fundet nogle galleri scripts på nettet.. Jeg har fået lavet så man kan uploade et billede til en mappe osv.. men jeg har problemer med, at få phpkoderne til at finde billederne. Der følger nu koderne over hvem enkelt fil jeg bruger..

Index.php ( Den der skal finde filerne, og lægge dem ind i galleriet..- Virker fint, hvis billederne har thumb_ inden navnet, men ikke alle, der uploader et billede, gider at skifte navnet på filen..)
Så hvis en kunne hjælpe mig med at "lave" så den finder alle filer der ender på .jpg istedet for starter med thumb_

<?
$td='4';
// BACKGROUND COLOR OF THE PAGE
$bg='white';
// SHOW THE NAME OF THE FILE?
$name='1'; // 1 = yes, 0 = no
// TITLE OF YOUR PAGE
$pagetitle='A selection of my images. Click each one to see a larger image.';

### --- CHANGE NOTHING BELOW THIS LINE UNLESS YOU ARE OK WITH PHP --- ###

// DIRECTORY NAME
$handle=opendir('.');

// GO
$piccy=array();
$count=0;
// SCAN THE DIR
while (($filename = readdir($handle))!==false) {
  // ADD IN EXTRA FILE TYPES HERE
  if (substr($filename,-4) == ".jpg" || substr($filename,-4) == ".gif" || substr($filename,-4) == ".png" || substr($filename,-4) == ".JPG" || substr($filename,-4) == ".GIF" || substr($filename,-4) == ".PNG"  || substr($filename,-4) == ".BMP" || substr($filename,-4) == ".bmp"){
  if (substr($filename,0,6) == "thumb_"){
    $piccy[$count] = $filename;
    $count++;
  }}}
// CLOSE DIR
closedir($handle); 
// SORT THE FILES
sort($piccy);
reset($piccy);

// DISPLAY LARGE IMAGE
if ($large){
        echo "<html><head><title>Easy Gallery :: " .$large. "</title></head><body bgcolor=" . $bg . ">";
  echo '<div align="center">';
// IS NAME SELECTED TO SHOW?
  if ($name=="1") {
      if (!(file_exists($large))){
          echo "No file of that name is uploaded.";
          exit;
      }
      echo '<br><font face="verdana" size="1">Selected image: ' . $large . '</font>';}
// SHOW THE PICTURE
  echo '<table width="100%" border=0 cellpadding=0 cellspacing=0>';
  echo '<tr>';
  echo '<td valign="middle" align="center"><a href=java script:history.back(-1)><img src="'.$large.'" alt="'.$large.'" border=0></a></td>';
  echo '<br>';
  echo '</tr></table>';
  echo '<br><br>';
  echo '<a href=java script:history.back(-1)>';
  echo '<font face="verdana" size="1">Back to the Thumbnail Gallery</font></a>';
        }
// NO LARGE PICCY, CREATE TABLE FOR THUMBNAILS:
else{
// start table, if you want cellpadding, cellspacing, colors, set them here
echo '<html><head><title> ::// Easy Gallery //::</title>';
echo '<head>';
echo "<body bgcolor=" . $bg . ">";
echo '<div align="center"><font face="verdana" size="1">' . $pagetitle . '</font><br>';
echo '<br><table width="100%" border=0 cellpadding=0 cellspacing=0>';
echo '<tr>';
// BECAUSE THE <TD> IS SET BY USER, WORK OUT THE PERCENTAGES:
$divider=ceil(100/$td);
if (($divider*$td)>100) $divider--;
// GRAB THE IMAGES
for ($l=0;$l<=sizeof($piccy)-1;$l++){
  $isend = strpos((($l)/$td),".");
  if (!$isend && ($l!=0)){echo "</tr>\n<tr><td colspan=$td><br></td></tr>\n<tr>\n";}
  if ($l==0){echo "\n";}
  // START THE <TD>
  echo '<td width="'.$divider.'%" valign="middle" align="center">';
  // GET THE LARGER PICTURE (IF SELECTED)
  echo "<a href=\"$PHP_SELF?large=".substr($piccy[$l],6)."\">";
  // DISPLAY THE THUMBNAILS
  echo '<img src="'.$piccy[$l].'" alt="'.$piccy[$l].'" border=0></a><br><br>';
  // IS NAME SELECTED TO SHOW?
  if ($name=="1") {
  echo '<font face="verdana" size="1">' . substr($piccy[$l],6) . '</font>';}
  echo '</td>';
  echo"\n";}
  echo '</tr></table></div>';}
  echo '<br><br><br><div align="center"><font face="verdana" size="1">Easy Gallery v1.2 :: <a href="</a></font></div></body></html>';
?>